[AngryData]

Well the sheer volume and high percetages of users that do it make it difficult. Despite what people try to pretend the Chinese government can't arbitrarily decree things without pushback and political fallout for it. You can't arrest all offenders if it means holding tens of millions people in detention. And trying to ban porn completely is going to piss off a massive percentage of their population, even if they don't say it directly.